From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756042AbcARRcn (ORCPT ); Mon, 18 Jan 2016 12:32:43 -0500 Received: from mail-lb0-f194.google.com ([209.85.217.194]:35294 "EHLO mail-lb0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755909AbcARRcj (ORCPT ); Mon, 18 Jan 2016 12:32:39 -0500 Date: Mon, 18 Jan 2016 18:32:36 +0100 From: Johan Hovold To: Konstantin Shkolnyy Cc: johan@kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/4 RESEND] USB: serial: cp210x: New register access functions. Message-ID: <20160118173236.GF3169@localhost> References: <1452973584-18284-1-git-send-email-konstantin.shkolnyy@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1452973584-18284-1-git-send-email-konstantin.shkolnyy@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 16, 2016 at 01:46:24PM -0600, Konstantin Shkolnyy wrote: > cp210x_get_config and cp210x_set_config are cumbersome to use. This change > introduces new register access functions to replace them. New functions > are not yet called - the switch is done gradually in following changes. > > Signed-off-by: Konstantin Shkolnyy > --- > change in v3: Presented new function addition as a separate patch #1, > to simplify code review. Thanks for the v3. You should not be adding (static) functions before they have a caller as this generates compiler warnings. Please define the new helper functions when converting their call sites. You can split the 8, 16 and 32-bit helpers in separate patches and possibly also separate read and write if that makes sense in order to keep the diffs smaller. > drivers/usb/serial/cp210x.c | 166 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 166 insertions(+) > > diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c > index fd67958..324eb7e 100644 > --- a/drivers/usb/serial/cp210x.c > +++ b/drivers/usb/serial/cp210x.c > @@ -323,6 +323,172 @@ struct cp210x_comm_status { > #define PURGE_ALL 0x000f > > /* > + * Reads a variable-sized block of CP210X_ registers, identified by req. > + * Returns data into buf in native USB byte order. > + */ > +static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req, > + void *buf, int bufsize) > +{ > + struct usb_serial *serial = port->serial; > + struct cp210x_port_private *port_priv = usb_get_serial_port_data(port); > + void *dmabuf; > + int result; > + > + dmabuf = kmalloc(bufsize, GFP_KERNEL); > + if (!dmabuf) { > + /* > + * FIXME Some callers don't bother to check for error, > + * at least give them consistent junk until they are fixed > + */ > + memset(buf, 0, bufsize); Instead of adding these FIXMEs and possibly risk introducing regressions (these functions used to leave the previous values unchanged on errors), how about adding the missing error handling first? > + return -ENOMEM; > + } Thanks, Johan